Well pipe elevator trunnion



Aug. 16, 1932. N. K: SMITH 1,871,925

WELL PIP E ELEVATOR TRUNNION 2 Sheets-Sheet 1 Original Filed Dec. '7, 1929 In ventor Ammcys Aug. 16, 1932. N. K. SMITH WELL PIPE ELEVATOR TRUNNION Original Filed Dec. 7, 1929 2 Sheets-Shee 2 ure 2,- thus pins Patented Aug. 16, 1932 UNITED STATES PATENT GFFIQE WELL PIPE ELEVATOR TRUNNION' Original application filed December 7, 1929, Serial No. 412,479. Divided and this application filed June 8,

This invention relates to elevator clamps for lowering or lifting pipe, casing, tools and similar objects in and out of wells.

An object of the invention is to provide a simple, yet adequate, trunnion construction on an elevator clamp that will permit the clamp to open without resistance from the loop bails or elevator links supporting it.

This application is a division of my application Serial No. 412,479, filed December 7, 1929.

In the acompanying drawings illustrating the invention:

igure 1 is a plan view of an elevator clamp accordance with the invention; igure 2 is a rear elevational view of the same device showing, in addition, fragments of the elevator links;

igures 3 and 4 are bottom views of the ele vator, in closed and opened positions respeccut away to show the trunnions; and

Figure 5 is a perspective view of one of e trunnions of my elevator.

\eferring to Figure 1, the elevator clamp comprises two main clamping members 1 hinged by pins 3 to a yoke 2 at the rear end. The particular manner of hinging the members 1 to the yoke 2 is clearly shown in Fig- 3 pass through ears 14 pro- Jecting from clamping member 1, and cars 15 projecting from yoke 2. Figure 1 shows the device in closed position in which the innor surfaces 12 of member 1, together with the inner surface 13 of the yoke 2, form a or tubing to be handled.

In their closed position, clamps 1 are locked together by a latch mechanism, represented at 7. This latch mechanism is described and claimed in my original application, but it may be of any well-known type of construction and the type employed is not material to the present invention. Its only function is to firmly unite the free ends of members 1 when the device is set in clamping position.

In use, the elevator clamp is attached to the hoisting mechanism by elevator links which engage trunnions 4 on the clamping members Trunnions 4 project laterally, and, prefer- Serial No. 542,752.

ably, radially from the body of the clamp. In the drawings each trunnion is shown divided by a slot within which is mounted a keeper 6 for preventing the elevator links 11 from becoming accidentally detached from the trunnion. This slotted construction, however, is immaterial to the present invention, and may or may not be employed.

rear lower edges 20 of the trunnions being substantially horizontal.

It is in this particular trunnion construction that my invention resides since it is the usual practice to curve the entire undersurfaces of both trunnion members to insure that the elevator links will not slip outward along the trunnions, but will lie against the body of the elevator. However, this usual construction tends to prevent the necessary rotary displacement between the elevator links and the when the elevator clamp is open,

inflexibly secured together at their upper ends ey cannot rotate freely with the Figure 4, when the clamp is open, the members 1 swing outand backward about pivots 3, so that the opposite trunnions, instead of lying in a common plane, lie in planes which intersect at an angle less than 180. This forces each trunnion to rotate at a slight angle with respect to the link which supports it. Where, in accordance with the prior practice, the entire lower surface of the trunnions extends outward and downward, the links are retor:

stricted against free rotation with respect to the trunnion and prevent free opening of the elevator.

lVith my improved construction, since the projections 9 are limited to a horizontal area on the front halves of the trunnions 4, and the rear lower edges are substantially horizont-al and level with the highest portion of the front edge, the links are free to slide outward along the rear edge of the trunnions as shown in Figures 4t and 5, and do not offer any objectionable amount of resistance opening of the elevator. Furthermore, they do not tend to automatically close the eleva' tor after it has been opened and let go of by the operator.

I claim:

1. An elevator of the character described comprising a pair of doors having concave pipe encircling recesses in their inner faces, means pivotally connecting said doors together at their rear ends, a trunnion extending laterally from each door, the trunnions being substantially straight in a lateral direction and having undersurfaces of uneven contour, such that the undersurface of each trunnion at the front edge is concave and at the rear edge is substantially horizontal and level with the highest point of the concave surface at the other edge.

2. An elevator of the character described comprising a pair of doors having concave pipe encircling recesses in their inner faces, means pivotally connecting said doors at their rear ends, trunnions extending laterally from the doors, the trunnions being parallel in the closed position of the elevator and having their front lower edges slanted downwardly and outwardly, and having their bottom rear edges substantially horizontal in a radial direction.

3. In an elevator clamp of the character described, a pair of clamping members hingedly secured together on one side and forming in closed position a substantially vertical opening therethrough, a trunnion extending radially from each clamping memher, the lower surface of the front half of each trunnion being concavely curved and the lower surface of the rear half of each trunnion being substantially horizontal and level with the highest portion of the curved surface of the front half.

Signed at Los Angeles, California, this 26th day of May, 1931.

NELSON K. SMITH.

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